Backup Switch For The Auxiliary Controller May Be Wired Incorrectly Caterpillar

Backup Switch For The Auxiliary Controller May Be Wired Incorrectly

Usage:

EXCAVATORS320B (1XS1-774),
320B L (7JR1-1498, 9WS1-179, 6LW1-326),
320B LN (3YZ1-441),
320B S (5MS1-425),
322B L (2ES1-694),
322B LN (1ZS1-386),
325B L (6DN1-914, 4DS1-166, 5BS1-220),
325B LN (8FN1-769),
330B L (3YR1-825, 4RS1-405, 5LS1-218),
330B LN (5LR1-514),
345B L (7KS1-398, 2SW1-120) EXCAVATORS

Reference: Operation & Maintenance Manual 320B, 322B, 325B Excavators; SEBE6988-03; June 1998. Operation & Maintenance Manual 330B Excavators; SEBE7021-01; February 1998. Operation & Maintenance Manual 345B Excavators; SEBE7116-01; July 1998.

Problem:

PROBLEM: Some machines in the list of ranges that are shown may have the auxiliary controller backup switch wired in a reverse position. Machines with a higher PIN have the backup switch correctly installed.

Illustration 1 shows the location of the backup switch in question. The right-hand view shows the correct position for the backup switch. The switch should be in the far right position for the AUT or automatic (normal) function. The switch should be in the far left position for MAN or the manual (backup) function.

In the manual position, the backup switch disconnects the controller circuit of the auxiliary controller. This condition allows the machine to work normally with all of the other functions.

Illustration 1. Location and positions of Auxiliary Backup Switch

Another test to verify the status of the Auxiliary Controller is to observe the indicator lights inside the cab. The indicator lights are located on the cover for the top wiper motor of the front windshield. The location for the indicator lights is shown in Illustration 2.

Illustration 2. Location of Indicator Lights

Yellow indicator light.

Orange indicator light.

If the Auxiliary Controller backup switch is in the automatic position, either the yellow indicator light or the orange indicator light will be on to indicate the position of the auxiliary ball valve. When the backup switch is in the manual mode, the Auxiliary Controller is disconnected and the indicator lights are off.

Solution:

If the backup switch toggle positions are the reverse from those shown in Illustration 1, the procedure for correcting the backup switch activation would be to switch the two wires to establish the correct activation for the backup mode. Illustration 3 shows the correct wire position for activating the switch.

Illustration 3. Position of wires for activating backup switch.